Oblateness

Oblateness is a word that describes how round or squished something is. Imagine you have a ball that is perfectly round, like a basketball. This ball has no oblateness.

But now imagine you take that same basketball and press on it really hard with your hands on the top and bottom. This will make the ball look a little more like a football, where it's round in the middle but squished a little bit on the top and bottom. This ball now has oblateness because it's not perfectly round anymore.

In space, planets and other celestial objects can also have oblateness. When a planet is formed, it's spinning around and around like a top. This spinning can cause the planet to bulge out around the middle and flatten out a little bit on the top and bottom. This makes the planet look more like a squished ball than a perfectly round one.

Scientists measure oblateness by looking at the difference between the diameter at the equator (the middle of the planet) and the diameter at the poles (the top and bottom of the planet). The bigger the difference between these two diameters, the more oblate the planet is.

So, oblateness is a word that describes how round or squished something is, like a ball or a planet. It happens when things are spinning and can cause objects to be a little more squished in the middle and flatter on the top and bottom.